The Importance of Advanced Materials

Nanostructured materials have also been formed by scanning tunneling microscopy (STM) [24], scanning electrochemical microscopy (SECM) [25], and atomic force microscopy (AFM) [26], Recent reports on the modification of atomic sites at bare surfaces by STM [27] and the formation of nanometer-scale defects by STM [28] and AFM [29] illustrate the power of these techniques. 

Differences between nanophysics and nanochemistry have been lucidly delineated in a recent review on nanochemistry [6]. The aim in nanophysics is to generate small particles by reducing the size of bulk materials by using engineering-type manipulations. Conversely, nanochemists synthesize their materials by chemical reactions from atoms-up . A synergetic combination of these two approaches should not be overlooked, of course. 

The term artificially structured materials implies a construction similar to nanostructured materials on a somewhat larger, on the whole unspecified, scale. The terms biomaterials and genetically engineered materials are self explanatory. 

Advanced materials are of paramount importance for the future of the electronics industry. Remarkable progress has been made in fitting increasingly greater numbers of components into an integrated circuit. This is illustrated by the often-shown electronic device density versus time semilogarithmic plot (Fig. 3) [30], as well as by the notebook computer, alluded to earlier. The 

The time has come to make a quantum leap, both figuratively and literally. Short-term solutions may exploit organic semiconductors [31-33] and semiconductor quantum heterostructures [34, 35]. A long-term solution will be provided by molecular electronics [36-40] in which single molecules are employed as integrated circuits [41, 42]. 

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